1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Not Available
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
1.6 Cleavage
Not Available
Perfect on [10 1 1] three directions with angle of 74° 55
1.7 Mohs Hardness
1.8 Chemical Composition
NaFe 3+ 3 Al 6 (BO 3 ) 3 Si 6 O 18 (O,F,OH) 4 Anthony et al, Handbook of mineralogy (2001)
CaCO 3Ulrich Henn and Claudio C.